Replacement Particle Image Velocimetry (PIV) Laser

正确表征流体流动需要在整个流场上进行精确的速度测量。当我们在空间中的许多点上同时获得关于流动的信息时，就可以更好地理解流场的物理性质。计算机技术和数字成像技术的快速发展促进了粒子图像测速技术的发展。要执行PIV，流被接种了微小的颗粒（如烟雾或薄雾），并使用强大的激光照射。然后，使用高速摄像机捕获流的两个连续图像，并使用复杂的粒子跟踪算法进行比较。最终结果是整个流场的速度矢量的完整阵列。** UNB目前拥有一个LaVision立体PIV系统，该系统工作状态良好，但照亮流动的激光器已老化，不再正常工作。我们的激光器制造商已被出售，不再生产PIV激光器。考虑到维修现有激光器的成本与购买新激光器的成本相当，并且考虑到激光器的某些组件已不再生产，我们认为最好的方法是购买新的替代激光器，以便我们可以再次进行PIV。因此，我们要求拨款更换一台功率与旧激光器相当的激光器。替代激光器具有防震设计，不需要定期光束对准;这意味着激光器比当前激光器更安全，因为激光器的光学室不需要定期打开。这种防震设计特别适合于我们对加速流动的研究。**

Properly characterizing fluid flows requires accurate velocity measurements over the full flow field. A better understanding of the physics of the flow field is gained when we have simultaneous information about the flow at many points in space. Rapid advances in computing and digital imaging have facilitated the development of the Particle Image Velocimetry (PIV) measurement technique. To perform PIV, a flow is seeded with tiny particles (like smoke or mist) and illuminated using a powerful laser. Then, two successive images of the flow are captured using high speed cameras and compared using complex particle tracking algorithms. The end result is a full array of velocity vectors throughout the flow field.******UNB currently has a LaVision stereoscopic PIV system that is in good working order but the laser that illuminates the flow is old and no longer working properly. The manufacturer of our laser has been sold and are no longer making PIV lasers. Given that the cost of repairing the current laser is comparable to the cost of buying a new laser and given that some components of the laser are no longer being made, we believe that the best way forward is to purchase a new replacement laser so that we can again perform PIV. Thus, we are requesting funds for a replacement laser of comparable power to the old laser. The replacement laser has a shockproof design that does not require regular beam alignment; this means that the laser is safer to use than the current laser as the optical chamber of the laser does not need to be regularly opened. The shockproof design is particular suited for our research on accelerating flows. **